public enum PerlOperator: String {
	case lt, lte, gt, gte, eq
}

public enum PerlFormat: String {
	case json, xml, jqm
}

public struct SearchNutrimentEntry {
	public let nutriment: SearchNutriment
	public let op: PerlOperator
	public let value: Int
}

public struct SearchTagsEntry {
	public let tag: SearchTag
	public let value: String
	public let contains: Bool = true
}

//https://wiki.openfoodfacts.org/API/Read/Search#Parameters
public struct PerlSearchQuery {
	public var searchTerms: String
	public var searchTags: [SearchTagsEntry]?  // tagtype_i=SearchTag — i as #element (starting from 0); (tag_contains_i|tag_does_not_contain_i)=String
	public var searchNutriment: [SearchNutrimentEntry]?  // nutriment_i=SearchNutriment — i as #element (starting from 0); nutriment_compare_i=PerlOperator; nutriment_value_i=String
	public var page: Int = 1  // Pagination
	public var format: PerlFormat  // json=1 | xml=1 | jqm=1

	public init(
		searchTerms: String, searchTags: [SearchTagsEntry]? = nil,
		searchNutriment: [SearchNutrimentEntry]? = nil, page: Int = 1,
		format: PerlFormat = .json
	) {
		self.searchTerms = searchTerms
		self.searchTags = searchTags
		self.searchNutriment = searchNutriment
		self.page = page
		self.format = format
	}

	public func makeToRequest() -> String {
		var _searchTags: String?
		var _searchNutriment: String?
		let _format: String = "\(format.rawValue)=1"
		let _page: String = "page=\(page)"
		if let tags = searchTags {
			_searchTags = tags.enumerated().map { i, v in
				return
					"tagtype_\(i)=\(v.tag.rawValue)&tag_contains_\(i)=\(v.contains ? "contains" : "does_not_contain")&tag_\(i)=\(v.value)"
			}.joined(separator: "&")
		}
		if let nutriments = searchNutriment {
			_searchNutriment = nutriments.enumerated().map { i, v in
				return
					"nutriment_\(i)=\(v.nutriment.rawValue)&nutriment_compare_\(i)=\(v.op.rawValue)&nutriment_value_\(i)=\(v.nutriment.rawValue)"
			}.joined(separator: "&")
		}

		return
			"search_terms=\(searchTerms)\(_searchTags != nil ? "&\(_searchTags!)" : "")\(_searchNutriment != nil ? "&\(_searchNutriment!)" : "")&\(_page)&\(_format)"

	}
}